Displays that by themselves always elicited chance judgment of number were shown to three- to four-year-olds and six- to seven-year-olds. The first display was transformed into the second, and so on. Results indicated that three- to four-year-olds do not understand conservation of number because judgements of successive displays were independent…

To investigate the development of function concepts and their relation to mathematical and logical abilities typically acquired during the age period of five to seven years, children were tested on nonnumerical function tasks, numerical tasks, and aspects of logical reasoning. (PCB)